This invention relates generally to packaging and to flexible packaging. More particularly, this invention relates to packages made from flexible packaging material having an opening sealed by a peelable seal that may be hand opened.
Flexible containers or packages formed of sheet materials have been used for many years and have wide acceptance for holding various air-perishable products, e.g., coffee and other foodstuffs. Prior art flexible, air-tight packages are commonly constructed of some plastic film, metal foil, or combinations thereof, in one or more plies and sealed along one or more seams. Such packages are usually vacuumized after filling but prior to sealing so that the contents of the package are not exposed to the degradation effects of air. Accordingly, products held in such packages can have a shelf life comparable to rigid packages, such as jars with screw-on lids or metal cans.
The advantages of flexible packages over rigid packages are many. For example, flexible packages can be manufactured at substantially lower cost and can be stored flat, thereby resulting in enormous space savings over rigid packages. Moreover, flexible packages are substantially lighter in weight, thereby resulting in reduced transportation costs for unfilled packages. Further still, flexible packages are generally of an overall parallelepiped shape when filled so that such packages take up considerably less shelf or storage space. Needless to say, this feature is of considerable importance insofar as transportation, storage, and display are concerned.
It is common practice to construct the package or bag by heat sealing laminated material to form the package. The package is then filled and its opening typically heat sealed closed to produce the final product for shipment. Packages of the above description may be used in vacuum packing, a familiar technique in which the contents are exposed to a reduced atmosphere during the sealing operation to draw off air or to eliminate gasses which otherwise might evolve or diffuse out of products over time. The present invention may be used, to equal advantage, with vacuum, non-vacuum, or gas-flushed packages.
The seals for packages of the above-described type must of course be strong enough to withstand routine handling and foreseeable mishandling, and to avoid spillage due to failure of the closure. Also, the closure must be strong enough and permanent enough to resist tampering. In typical prior art packages, the seals are often as strong as the other seams of the package. Opening may require the use of knives, scissors or other cutting instruments. As an alternative, schemes have been proposed for the use of frangible elements, tear strips or drawstrings, to facilitate opening. Each of these in some measure complicates the production process, and results in partial or complete destruction of the package upon opening. This latter attribute is itself undesirable, for in the marketing of certain products, it is common to open the package, process the contents (as, for example, in the grinding of coffee beans), and return the processed contents to the package.
While prior art air-tight, flexible packages exhibit the aforementioned advantages over rigid packages, there are still some undesirable characteristics, particularly when it is desired to be able to open and reclose the package after its initial opening. In this regard, as indicated above, the seams of prior art flexible packages are usually permanent in the interest of air tightness and structural integrity and are commonly formed by conventional heat sealing or welding techniques. Thus, the prior art flexible package is typically opened by cutting or tearing one or more of its seams.
Additionally, in the prior art, there is a plastic bag with a peelable portion to form a spout disclosed in U.S. Pat. No. 4,953,708 to Beer. There are many other examples of packages with peelable seal openings, both patented and commercially available. Easy access to a granular product packaged in a flexible material can be provided as described in U.S. Pat. No. 4,518,087 to Goglio.
Another flexible package is disclosed in U.S. Pat. No. 4,488,647 to Davis. Here, the peal seal is not provided in a pattern, but is continuous around the upper end portion of the package such that the adhesive extends into the heat sealed seams, thereby reducing the structural integrity of the package.
Generally, the prior art discloses methods of gaining entry to a package. But, there is no concern that the opening would extend into a sealed corner.
The present invention provides a flexible package which features an easy opening peel seal which can be manufactured in a variety of strengths, and which, unlike known previously existing peel seals is sufficiently strong to meet all of the usual requirements, including the ability to reliably retain vacuum. Another aspect of the novel peel seal of the present package is extreme simplicity of manufacture, in which the making of the seal lends itself to continuous processes of the kinds used to make and fill packages.
Importantly, the area of the peel seal of the present invention does not interfere with the other permanent seams of the package. The process of applying a coating to predetermined area of a laminate web is generally referred to in the flexible packaging industry as xe2x80x9cpattern coatingxe2x80x9d. The peel seal is placed on the laminated material by the xe2x80x9cpattern coatingxe2x80x9d wherein the peal seal adhesive is placed away from the heat sealed seams and placed in a pattern only on that portion of the laminate that is actually pealed opened. Therefore, the structural integrity of the main seams is maintained.
Accordingly, it is a general object of the present invention to provide flexible packaging and a method for producing the same which overcomes the disadvantages of the prior art.
It is a further object of the present invention to provide flexible packaging having an air tight sealed upper end which can readily be pulled open without resulting in the destruction or tearing of any portion of the package, particularly the seams, thereby enabling the package to be reclosed.
It is still a further object of the present invention to provide a flexible package having an open upper end which is sealed by a peelable interface between abutting wall portions of the package and which interface can be readily peeled open without destroying any portion of the package.
It is yet another object of the present invention to provide a flexible package having an open upper end which is sealed by a peelable interface between abutting wall portions of the package wherein the peel seal adhesive does not extend into the area of the permanently sealed corners of the package such that the corners remain permanently sealed to give the package a desired squared off appearance and structurally secure seams.
It is still another object of the present invention to provide a method for producing a flexible package having an air-tight sealed mouth which can readily be peeled open without resulting in the destruction of any portion of the package, particularly, the seams.
It is a further object of this invention to provide a simple and economically viable method for producing a flexible package which is sealed by a peelable interface between abutting wall portions of the package and which interface can be readily opened without destroying any portion of the package, particularly the seams.
These and other objects of this invention are achieved by providing a package fabricated from a flexible sheet material capable of being sealed for closing off the interior of the package from ambient atmosphere. The package has two or more side walls and a like number of side seams. The package has an open upper end portion terminating in a free edge. The inner surface of the side walls has a releasably securable adhesive adjacent the upper end portion in a pattern wherein the adhesive does not extend into the side seams, thus increasing the structural integrity of the package. A method of producing the package is also provided.
The flexible package with sealed edges and easy to open mouth is designed to hold a free flowing product such as coffee (beans or ground), powdered drink mix, ready to eat breakfast cereal, lawn/garden chemicals, and the like. The package utilizes sealed vertical edges to provide a pleasing visual appearance and to provide support for the package to prevent sag. The mouth of the package is closed with a peel seal enabling the package to be opened by simple hand manipulation.
By applying the peal seal material only to the area of the package requiring opening, and specifically stopping the peel seal material prior to extending into the sealed corners, those corners remain permanently sealed to give the package the desired squared off appearance. Furthermore, if the package is made from a single sheet of laminated material, one of the four corner seals joins the edges of the sheet. If this seal were peelable, the bag formed from the sheet would separate at this seam, thus spilling the contents of the package.